HF RF Transistor Parameter Extraction for LF

spflanze — Tue, 11 Jun 2019 23:10:02 GMT

I am seeking to use this BFU520A transistor:

https://www.nxp.com/docs/en/data-sheet/BFU520A.pdf

or one like it to create a 40 MHz transimpedance amplifier of topology described by Phil Hobbs in Figure 9, page 4, of this article:

https://electrooptical.net/static/oldsite/www/frontends/frontends.pdf

I consider the BFU520A because of its very high Ft which means there would still be a lot of gain to do the bootstrapping at 40 MHz.

I seek to optimize the resistor values for the resistors in Figure 9. The data for that transistor does not go down to 40 MHz and below which is where I need it. To optimize my concern is how to determine what Beta, and Base Spreading Resistance, to use from 0 to 40 MHz, as a function of collector current, from the data available. Any suggestions are appreciated.

Re: HF RF Transistor Parameter Extraction for LF

LPP — Tue, 18 Jun 2019 09:16:11 GMT

NXP provides models of BFU520A. You can use them to simulate the circuit or extract required parameters for your job.

SPICE model:

https://www.nxp.com/downloads/en/spice-model/BFU5XX_family_SPICE_GP_v2.zip

MEXTRAM model for Keysight ADS:

https://www.nxp.com/downloads/en/design-support/Installation_manual_for_NXP_BFU5XX_family_ADS_design_kit_v2.pdf
https://www.nxp.com/downloads/en/design-support/BFU5XX_family_ADS_design_kit_v2.zip

Have a great day,

Pavel
TIC

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topic HF RF Transistor Parameter Extraction for LF in Other NXP Products

HF RF Transistor Parameter Extraction for LF

Re: HF RF Transistor Parameter Extraction for LF